Hells Canyon And Snake River
William H. Mullins
Chiricahua National Monument
Mark Newman
Volcanic Rock
Photo Researchers
Volcanic Rock #1
Photo Researchers
Volcanic Rock With Lichen
Richard and Ellen Thane
Volcanic Neck
James Steinberg
Volcanic Tuff
William H. Mullins
Volcanic Ash In Oregon
William H. Mullins
Rock Dwellings
Alison Wright
Rock Formations Of Cappadocia, Turkey
Alison Wright
Basalt, An Igneous Rock
Andrew J. Martinez
Church Rock, Arizona
James Steinberg
Balanced Rock, Idaho
William H. Mullins
Balanced Rock, Idaho #1
William H. Mullins
Balanced Rocks, Chiricahua Nm
James Steinberg
Balanced Rocks In Arizona
James Steinberg
Olmec Head, La Venta
Helen Marcus
Sierra Negra
Tierbild Okapia
Poipu Area On The Island Of Kauai
Kenneth Murray
Snowflake Obsidian #1
Andrew J. Martinez
Obsidian
Andrew J. Martinez
Ropey Lava
Karl H. Switak
Rhyolite
Andrew J. Martinez
Scoria
Andrew J. Martinez
Obsidian And Pumice
Chris Bjornberg
Basalt
Andrew J. Martinez
Vesicular Basalt #1
A.b. Joyce
Columnar Basalt
William H. Mullins
Obsidian #1
Andrew J. Martinez
Snowflake Obsidian
Andrew J. Martinez
Pumice
Photo Researchers, Inc.
Pumice #1
Photo Researchers, Inc.
Pumice #2
Photo Researchers, Inc.
Pumice #3
Photo Researchers, Inc.
Pumice #4
Photo Researchers, Inc.
Pumice #5
Photo Researchers, Inc.
Pumice #6
Photo Researchers, Inc.
Pumice #7
Photo Researchers, Inc.
The Devils Tower National Monument
Rafael Macia
Welded Tuff
William H. Mullins
The Steuchans, Giants Causeway, 1890s
Science Source
Honeycombs, Giants Causeway, Ireland
Science Source
Pleaskin Head, Giants Causeway, 1890s
Science Source
Giants Causeway, 1890s
Science Source
Pahoehoe Lava #1
David Hosking
Pahoehoe Lava #2
David Hosking
Sally Lightfoot Crab #2
William H. Mullins
Landscape, Lava Beds National Monument #1
Richard and Ellen Thane
Galapagos Islands
David Hosking
Closed Canyon, Texas
Greg Dimijian
Lava Flowing To The Sea
Phil Degginger
Chiricahua National Monument #1
Mark Newman
Chiricahua National Monument #2
Mark Newman
Columnar Basalt In The Grand Canyon #1
William H. Mullins
Banded Rhyolite
A.b. Joyce
Banded Rhyolite #1
A.b. Joyce
Banded Rhyolite #2
A.b. Joyce
Vesicular Basalt
A.b. Joyce
Pumice Layers
Chris Bjornberg
Chiricahua National Monument, Arizona
James Steinberg